The War Against Sand
Imagine living on the edge of a vast desert, which is moving quietly closer to your village every day and covering your fields. The desert is on the move. This is called desertification.
Desertification occurs in regions close to an already existing desert. 71 The first is over-use of water in the area. There is not enough water in any case, and if it is not carefully used, disaster can follow. As time goes on, water shortages make farming more and more difficult. In some places, locals can remember local lakes and marshes which were once the homes for all kinds of fish and birds. 72 Farmers leave the land, and fields are replaced by deserts.
The second cause is misuse or over-use of the land. 73 Ploughing(耕) large fields and removing bushes and trees means that the wind will blow away the soil. Once the soil is lost, it is hard to replace, and if there is rain, it has nowhere to go, and brings no benefit.
74 Every spring, the skies over some of eastern cities, thousands of kilometers away from the deserts, can be darkened by sandstorms. Dust from deserts can have a great effect on weather systems. While desertification is perhaps being partly caused by global warming, these sandstorms can make global warming worse by adding to what is known as the greenhouse effect.
What can be done to slow down or stop the process of desertification? A great deal of work is already under way. Obviously first steps are to find new water sources. 75 Some types of grass also hold the soil together, and stop the wind taking it. Without these efforts, it will be harder and harder to stop the world’s deserts in their tracks, and more and more farmers will give up and head for cities. The lesson to be learnt lies beneath the sand.A．It generally arises from two related causes.B．It is not only the farmers and villagers who suffer.C．They have been pletely buried by the sand now.D．Scientists are doing the research on the cause of desertification.E. They destroy the land, as the soil dries out and is then blown away.
F. Tree planting can help, by providing barriers between desert and rich field.
G. This means that the wrong crops are planted, and need more water than is available.A
网友回答
(答案→)A
解析：
【小题1】A 本段解释了荒漠化的两大原因，故A符合段落大意，故A正确。
【小题2】C 根据下面两句。农民离开，土地被掩埋可知他们已经完全被沙漠所掩埋。
【小题3】G 本段内容是关于错误使用或者过度使用土地或者水源，故G正确。
【小题4】Ｂ本段解释的是受到荒漠化影响的其他一些领域，如沙尘暴等，故B正确。
【小题5】F 本段讨论的是治理荒漠化的具体方法，种树是一个很有用的方法。